Hood tilt mechanism for curved glass processing

ABSTRACT

A glass forming assembly for forming complex shaped glass, with the glass forming assembly having a hood assembly including a hood lift superstructure movable horizontally back and forth over a cold ring and a cooling shuttle and movable vertically relative to the cold ring and the cooling shuttle, and a hood frame supported by the hood lift superstructure by a hood tilt mechanism. The hood tilt mechanism includes an air cylinder assembly actuable to tilt the hood frame relative to the hood lift superstructure, which allows for proper orientation of the glass prior to dropping it on the cooling shuttle, thus allowing for reduced glass chipping and cracking.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. nonprovisional patentapplication Ser. No. 10/205,065, filed Jul. 25, 2002, which isincorporated herein by reference.

BACKGROUND OF INVENTION

The present invention relates to glass forming and transport mechanisms,and in particular to glass forming and transport mechanisms to shapecurved glass, such as, for example, glass in vehicles.

Glass components used in automobiles, such as windshields, are oftencomplex shaped parts. During the shaping process, hot glass enters avacuum mold and is shaped close to its final shape. The glass needs tobe brought into the mold at a predetermined angle on a hot ring in orderto allow for proper shaping. The mold drops down and picks up the glassoff of the hot ring via vacuum pressure. The hot ring is removed, andthen a cold ring is brought under the glass, with the glass releasedonto the cold ring from the mold. The glass is then picked up by a hoodvia a vacuum pressure. The hood has teeth that are adjustable and, sincethe glass is still hot, can shape the glass slightly. So, if the hood ismis-adjusted, the glass can be mis-shaped. The hood transports the glassover the top of cooling conveyor pads on a shuttle (a cooling conveyerwith fans for cooling the glass). Since it is glass, and so somewhatbrittle, the glass must be at the proper angle when dropped onto thepads of the shuttle or it has a greater tendency to chip or crack. Forparticularly complex shaped glass, such as vehicle windshields withcomplex curvature, assuring the proper angle can be difficult,especially since, for the complex shaped glass, this angle can bedifferent than that needed in the mold. The orientation of the glassduring the shaping process, then, is typically driven by the need for aproper orientation of the glass as it is placed on a cooling shuttlefrom a hood. If the placement of the glass on the cooling shuttle doesnot allow for the glass to contact all of the shuttle pads essentiallyat the same time, the glass will have a tendency to chip and crack.Since conventionally, the tilt of the hood is fixed, the glass tiltrelative to the shuttle pads cannot be adjusted while the hood is movingthe glass from the cold ring to the shuttle. Because of this, theorientation of the glass as it is brought into the vacuum mold would notbe optimum.

In order to assure the proper angle at the time of dropping the glassonto the shuttle pads, then, and assuring optimum orientation of theglass in the vacuum mold, the glass forming process requires the use ofan articulated hot ring tool when forming the complex shapes. Anarticulated hot ring has hinges on a pair of opposite sides (for awindshield, this is typically the driver and passenger sides). Butarticulated hot rings are generally not desirable if a non-articulatedhot ring can be employed instead. By employing a non-articulated hotring instead of an articulated hot ring, the cycle time for forming theglass can be reduced, there is less scrap because there won't be anyhinge kinks, as can happen with articulated tooling, as well as areduction in glass chips, which can occur when an air suspension blockdrops the glass onto the hinges of the articulated hot ring. Further,the tooling will require less maintenance because of the reduced numberof moving components.

Thus, it is desirable to have a glass forming system and process thatovercomes the drawbacks of the prior systems, which require anarticulated hot ring in order to form complex shaped glass parts andhave the glass at the optimum orientation when dropped onto the pads ofthe cooling conveyer.

SUMMARY OF INVENTION

In its embodiments, the present invention contemplates a glass formingassembly for forming complex shaped glass. The assembly includes a coldring, a cooling shuttle, and a hood assembly. The hood assembly has ahood lift superstructure movable horizontally back and forth over thecold ring and the cooling shuttle and movable vertically relative to thecold ring and the cooling shuttle, a hood frame supported by the hoodlift superstructure by a hood tilt mechanism, with the hood tiltmechanism including an air cylinder assembly actuable to tilt the hoodframe relative to the hood lift superstructure.

An embodiment of the present invention allows for the adjustment of theorientation of a complex shaped glass part, such as a windshield, as itis carried by a hood, before it is dropped onto a cooling conveyer.

An advantage of the present invention is that, since the hood can tip,the glass can be brought into a vacuum mold on a hot ring at a betterorientation to the mold, without requiring the use of an articulated hotring. By eliminating the need for an articulated hot ring, cycle timefor glass forming, scrap, and maintenance time can be reduced.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic, front view of a portion of a hood employed in aglass forming process, in accordance with the present invention;

FIGS. 2 a-2 d are a schematic, side views of a portion of the hood shownin FIG. 1, as the hood moves through its portion of the glass formingprocess; and

FIG. 3 is a schematic view of a portion of the stations employed duringa glass forming process in accordance with the present invention.

DETAILED DESCRIPTION

FIGS. 1 and 2 a-2 d illustrate a hood assembly 12 portion of a glassforming assembly 10. The hood assembly 12 includes a hood liftsuperstructure 14, which is mounted to the glass forming assembly 10 andis only movable in the horizontal and vertical direction, and a hoodframe 16, which mounts to and is supported by the hood liftsuperstructure 14. The bottom side 17 of the hood frame 16 is shaped toreceive the glass and hold it by vacuum pressure. A first end of thehood frame 16 is pivotally mounted to the hood lift superstructure 14,while a second end is mounted to and supported by the hood liftsuperstructure 14 via a pair of hood tilt mechanisms 18.

The hood tilt mechanisms 18 each include an adjustable hood liftmounting bracket 20, which is fastened to the hood lift superstructure14 via slotted holes that allow for accurate alignment of the hood tiltmechanism 18 relative to the hood lift superstructure 14. Each of thehood tilt mechanisms 18 also include an adjustable clevis mount bracket22 under which an air cylinder 24 is pivotally mounted. Each aircylinder 24 then pivotally connects at its other end to a hood framebracket 26, which is preferably welded to the hood frame 16. The hoodframe brackets 26 preferably pivot about an axis that is at an angle ofabout ninety degrees from the pivot axis of the clevis brackets 22 inorder to allow for horizontal misalignment to accrue without damaging orhaving to reposition adjacent structures in the glass forming assembly10.

Each air cylinder 24 is connected to a pair of hoses 27, with each oneof the hoses 27 connecting to a different side of a piston (not shown)in the air cylinder 24, for telescopically actuating a rod 28 connectedto the piston. The other ends of the air hoses 27 are connected to asingle solenoid valve 30, which in turn, is connected to a conventionalsource of pressurized air (not shown). By connecting both sets of hoses27 to a single valve, the air cylinders 24 can act in unison whenraising or lowering that end of the hood frame 16. The valve 30 iselectrically connected 31 to and controlled by a controller 32, whichreceives input from other portions of the glass forming assembly 10 inorder to provide the proper timing for actuating the air cylinders 24.By actuating the cylinders 24, this allows for the hood frame 16 totilt, thus tipping the glass as it is supported by the hood frame 16,even though the hood lift superstructure 14 can only move horizontallyand vertically.

At one end of the hood lift superstructure travel, it will be locatedover pads 34 on a cooling shuttle 36; Located adjacent to the coolingshuttle 36 is a reed switch 38, which is electrically connected 40 tothe controller 32. When the hood frame 16 is over the pads 34 and theair cylinders 24 are extended, the reed switch 38 will be actuated andsend a signal to the controller 32 indicating that the cylinders 24 areextended. The controller 32 will then prevent the cooling shuttle 36from moving the pads 34 until the controller 32 receives an indicationfrom the reed switch 38 that the cylinders 24 have been retracted.

FIGS. 2 a-2 d and 3 illustrate several of the stations of the glassforming assembly and how the hood frame 16 is manipulated in order tomove the glass from one station to another. An air suspension block 44carries the hot glass 46 from a heating apparatus (not shown),supporting the glass 46 via a large vacuum/small positive pressure ontop of the glass 46 that suspends the glass just below the block. Thesolid outline of the particular station in FIG. 3 illustrates where theglass 46 is first supported by that station, while the phantom outlineof that station is where the glass 46 is released from that particularstation. The air suspension block 44 releases the glass 46 onto anon-articulated hot ring 48 at the desired angle for molding the glass46. The heated glass 46 on the hot ring 48 then moves, via a firstshuttle 50, into a vacuum mold 52. The mold 52 comes down and lifts theglass 46, via vacuum pressure, and molds it. While molding the glass 46,the hot ring 48 moves out from under the glass 46 and a cold ring 54,via a second shuttle 56, moves into the vacuum mold 52 under the glass46. The vacuum mold 52 lowers the glass 46 and releases it onto the coldring 54, which then moves out of the molding station 52. The hood 12moves over the top of the cold ring 54 in its up position, and then thehood lift superstructure 14 is lowered down to the cold ring 54 in itscold ring pick up position (position shown in FIG. 2 b). The hood 12picks up the glass 46, via vacuum pressure, off of the cold ring 54, andlifts it to its up position and moves horizontally over the top of thecooling shuttle 36 (position shown in FIG. 2 a). The hood 12 lowers thehood lift superstructure 14 down to an initial drop position (positionshown in FIG. 2 c). The controller 32 actuates the solenoid valve 30causing the rods 28 of the air cylinders 24 to extend downward, thustilting the hood frame 16 so that the bottom surface 17 of the hoodframe 16 will be essentially equidistant from the pads 34 of the coolingshuttle 36, and the reed switch 38 is activated (position shown in FIG.2 d).

The vacuum in the hood frame 16 is then released, dropping the glass 46onto the pads 34 at the proper orientation, thus avoiding chipping orbreakage. The controller 32 will then actuate the solenoid 30 in theopposite direction, causing the rods 28 to retract into the aircylinders 24 and deactivating the reed switch 38. Until the reed switch38 is deactivated, the controller 32 will prevent the cooling shuttle 36from moving the glass. As an alternative to handling all of themovements of the hood frame 16 sequentially, the air cylinder can beactuated to tilt the hood frame 16 as the hood lift superstructure 14 ismoving the hood frame 16 horizontally and/or vertically. The coolingconveyer 36 then moves the glass 46 past fans (not shown), allowing theglass 46 to cool.

In the case of a vehicle windshield, for example, the hood tiltmechanism 18 allows the roof edge of the windshield to be lowered at theunload position of the hood frame 16 such that the roof and cowl centersare horizontal, thus allowing for an even drop onto the pads 34 of thecooling shuttle 36. This even drop greatly reduces the chances forbreakage and stress fractures in the windshield. This allows for thewindshield glass to be brought in to the vacuum mold 52 at a betterorientation on the hot ring 48 since the hood 12 can tilt the windshieldto a different orientation prior to placing it on the cooling shuttle36. This better orientation allows the hot ring 48 to support the glassat the desired orientation without having to be articulated, thusreducing the cost of the hot ring 48, and improving the cycle time forforming the glass.

While certain embodiments of the present invention have been describedin detail, those familiar with the art to which this invention relateswill recognize various alternative designs and embodiments forpracticing the invention as defined by the following claims.

1. A glass forming assembly for forming complex shaped glass, theassembly comprising: a cold ring; a cooling shuttle; and a hood assemblyhaving a hood lift superstructure movable horizontally back and forthover the cold ring and the cooling shuttle and movable verticallyrelative to the cold ring and the cooling shuttle, a hood framesupported by the hood lift superstructure by a hood tilt mechanism, andwith the hood tilt mechanism including an air cylinder assembly actuableto tilt the hood frame relative to the hood lift superstructure.
 2. Theglass forming assembly of claim 1 wherein the hood tilt mechanismfurther includes a solenoid valve operatively engaging the air cylinderto thereby actuate the air cylinder.
 3. The glass forming assembly ofclaim 2 further including a controller operatively engaging the solenoidvalve to thereby activate the solenoid valve.
 4. The glass formingassembly of claim 2 further including a switch, with the switch beingactivatable when the hood tilt mechanism tilts the hood frame downwardrelative to the hood lift superstructure.
 5. The glass forming assemblyof claim 4 further including a controller operatively engaging thesolenoid valve and the switch to thereby activate the solenoid valve anddetect an activation state of the switch.
 6. The glass forming assemblyof claim 1 further including a vacuum mold; a cold ring shuttle uponwhich the cold ring is mounted, with the cold ring shuttle actuable tomove the cold ring into and out of the vacuum mold; a non-articulatinghot ring; and a hot ring shuttle upon which the hot ring is mounted,with the hot ring shuttle actuable to move the non-articulating hot ringinto and out of the vacuum mold.
 7. A glass forming assembly for formingcomplex shaped glass, the assembly comprising: a cold ring; a coolingshuttle; a hood assembly having a hood lift superstructure movablehorizontally back and forth over the cold ring and the cooling shuttleand movable vertically relative to the cold ring and the coolingshuttle, a hood frame supported by the hood lift superstructure by ahood tilt mechanism, and with the hood tilt mechanism including an aircylinder assembly actuable to tilt the hood frame relative to the hoodlift superstructure; a vacuum mold; a cold ring shuttle upon which thecold ring is mounted, with the cold ring shuttle actuable to move thecold ring into and out of the vacuum mold; and a non-articulating hotring; and a hot ring shuttle upon which the hot ring is mounted, withthe hot ring shuttle actuable to move the non-articulating hot ring intoand out of the vacuum mold.
 8. The glass forming assembly of claim 7wherein the hood tilt mechanism further includes a solenoid valveoperatively engaging the air cylinder to thereby actuate the aircylinder.
 9. The glass forming assembly of claim 8 further including acontroller operatively engaging the solenoid valve to thereby activatethe solenoid valve.
 10. The glass forming assembly of claim 8 furtherincluding a switch, with the switch being activatable when the hood tiltmechanism tilts the hood frame downward relative to the hood liftsuperstructure.
 11. The glass forming assembly of claim 10 furtherincluding a controller operatively engaging the solenoid valve and theswitch to thereby activate the solenoid valve and detect an activationstate of the switch.
 12. An apparatus for forming glass into a complexshape comprising: means for heating the glass; means for supporting theglass on a hot ring; means for moving the hot ring into a mold; meansfor shaping the glass; means for supporting the glass on a cold ring;means for moving the cold ring out of the mold; means for lifting theglass from the cold ring by vacuum pressure from a hood assembly; meansfor moving the hood assembly horizontally over a cooling shuttle; meansfor lowering a hood lift superstructure to be adjacent to the coolingshuttle; means for tilting a hood frame portion of the hood liftsuperstructure downward thereby reorienting the glass relative to thecooling shuttle; and means for releasing the vacuum pressure from thehood assembly to thereby drop the glass onto the cooling shuttle. 13.The apparatus of claim 12 further including means for activating aswitch as the hood frame portion is tilted downward; and means forpreventing the cooling shuttle from moving while the switch is actuated.14. The apparatus of claim 13 further including means for tilting thehood frame portion upward; and means for deactivating the switch as thehood frame portion is tilted upward.
 15. The apparatus of claim 12wherein the means for tilting the hood frame portion includes a solenoidvalve operatively engaging an air cylinder.